This invention relates to an arrangement for correction of laser radiation emanating from a laser light source, including a laser light source which has linear emission sources which are located essentially in at least one row in a first direction, furthermore the emission sources located essentially in a row being offset in the direction perpendicular to the first direction at least partially to the row, and the arrangement furthermore having correction means which can correct the laser radiation emanating from the laser light source such that the three-dimensional distortion of the laser radiation caused by the offsetting of the emission sources to the row is equalized. Furthermore this invention relates to a process for producing this arrangement.
An arrangement and a process of the initially mentioned type is known from U.S. Pat. No. 6,166,759. In the arrangement described, the so-called “smile” distortion, which generally occurs in laser diode bars, and which corresponds essentially to the bending of the row of emission sources, is corrected. The correction means is a glass fiber, which acts at the same time as a collimator lens, the glass fiber being aligned essentially parallel to the row of emission centers and thus to the first direction. Using these glass fibers at the same time, the fast axis divergence of the laser light proceeding from the laser diode bar is collimated. In order to be able to keep up with its correction function, the glass fiber is deliberately bent by means of an externally complex mechanical bending instrument, such that the light emanating from the individual emission centers which are offset to one another strikes the transverse side of the optical fiber facing the laser diode bar roughly in the center. In this way, the light beams emanating from the individual emission sources and passing through the optical fibers are made inherently parallel, but have a minimum beam offset against one another. In this arrangement, which is known from the art, it has been found to be especially disadvantageous that the instrument used for bending the glass fibers has a relatively complex structure, because the glass fibers at some points must be deliberately bent by only a few microns or fractions of microns relative to other points.
U.S. Pat. No. 5,854,651 discloses an arrangement and a process of the initially mentioned type in which plane-parallel plates are used as the correction means, among others. These plane-parallel plates are arranged in the beam direction downstream of a collimation lens for the fast axis and downstream of the focusing lenses for the slow axis and furthermore downstream of another focusing lens for the fast axis. The plane-parallel plates are tilted according to the previously measured “smile” distortion to the optical axis. The disadvantage here is that on the one hand for each of these plane-parallel plates according to the vertical offset of the assigned emission center of the laser diode bar an exact tilting angle relative to the optical axis must be set. On the other hand, it can be considered especially disadvantageous that this angle must be selected to be exceedingly exact as a result of the beam offset which is to be very exactly implemented. This can be done under certain circumstances only with very high cost.
It is one object of this invention is to devise an arrangement and a process of the initially mentioned type which can be more easily implemented.